Wool and other hair fibers have the most complex structures of all textile fibers. Wool is made of an intricate blend of proteins and other chemical substances. The thermal and mechanical responses of the fibers are determined by a variety of inter-atomic and inter-molecular bonds and a variety of structural forms. The wool fiber has a slightly and imperfectly elliptical cross section.
Benefits of wool fiber: The special features of structure of wool fiber are crimp, which leads to high bulk and softness, and scales, which lead to felting.
Delivering flexibility and absorbency: The cortical cells in the wool structure have a complex interior structure. The smallest component within these cells is a spring like structure which gives wool its flexibility, elasticity, resilience and wrinkle recovery properties. This spring like structure is surrounded by a matrix which contains high Sulphur proteins that readily attract and absorb water molecules.
Crimp adds soft touch: It makes soft and springy to touch. It also adds bulk and traps a large volume of air between the fibers, giving it good insulation properties.
The directional frictional effect: This allows fibers to slip over one another easily in one direction but not the other and giving wool the ultimate ability to felt.
Absorbency creates comfort: When wool absorbs moisture it produces heat so if you go from a warm room into a cold damp night wearing a wool jersey the wool picks up water vapor from the air keeping you warm.
Water repellent and tough surface: The cuticle cells provide a tough exterior, protecting the fiber from damage. The cells have a waxy coating, making wool water repellent, but still allowing absorption of water vapor.
Elastic recovery impact: In wet condition the wool fiber has complete recovery from extension up to 30%. The recovery behavior is an important structural feature of wool fiber. The composite structure of wool fiber is treated as a fibril with helical chains in parallel with an amorphous matrix, with the two linked at intervals to give a series of zones.
